Evacuated blood collecting apparatus



0 United States Patent 13,536,061

[72] Inventor Robert W.Ogle 3,123,073 3/1964 Barr Sr. et a] 128/276- p r B California 3,136,440 6/1964 Krug et a1. 215/47 5 a g Primary Examiner-Richard A. Gaudet 5 pafented a 1970 Assistant Examiner1(yle L. Howell Attorney-Finkelstein&Mueth [73] Assignee Tn-Po Stopper Corporation Wilmington, Delaware a corporation of Delaware [54] EVACUATED BLOOD COLLECTING APPARATUS 2 Claims, 4 Drawing figs.

[52] US. Cl 128/2, 128/276 [51] Int. Cl A61b 5/14 [50] FieldofSearch 128/2,

218, 218.1, 218.2, 220, 272, 276 (blood draw digest);

[56] References Cited UNITED STATES PATENTS 2,653,609 9/ 1953 Smith 128/272 2,460,641 2/1949 Kleiner 128/214 ABSTRACT: The present patent describes a novel evacuated blood sampling tube adapted for use with a blood sampling tube holder, and having an imperforate stopper providing an aspirating position, a sealing position and a puncturing position, and wherein only a slight force is required to move from the sealing to the perforating position, said stopper having along its axis a thin imperforate diaphragm portion, immediately above said diaphragm a hole having an inside diameter less than that of the needle and a length at least as long as the scarf of the needle, and above said hole, a communicating entrance hole having a diameter larger than said needle.

Patented Oct. 27, 1970 3,536,061

Sheet 1 01'2 2a .1; I v Fla-.4

W & N

l'f/l INVENTOR. 05667 M4 0666 ATTOKN-K? Y Patented Oct. 27, 1970 Sheetiof2 INVENTOR- 505557 W 0665 v BY EVACUATED BLOOD COLLECTING APPARATUS BACKGROUND OF THE INVENTION In the standard evacuated blood sampling tubes there is provided a plug in the open end of the sampling tube to seal the same. The plug is normally dimpled or dished on the inner and outer surfaces so that the center of the plug forms a diaphragm somewhat thinner than the thickness of the periphery of the plug. The thickness of the diaphragm is such that the inner point of the needle of the holder used in conjunction with the tube for the taking of blood by the vacuum method may be completely imbedded and sealed therein.

This construction is necessary so that the blood sampling tube and the holder can be partially preassembled before the placement of the other end of the needle into the vein from which the blood is to be withdrawn. If the parts were not thus preassembled the veinous blood pressure upon injection of the needle would cause blood to be discharged into the holder or onto the operator. Therefore, preassembly by imbedding the end of the needle in the stopper is required. The preassembled unit is normally placed in the vein and then by forward thrust on the tube, the puncturing of the stopper by the needle is completed to withdraw the blood. The procedure and structure discussed immediately above has several disadvantages. In order to prevent the unwanted discharge of blood into the holder or onto the operator it is necessary that the lumen of the needle be completely imbedded within the stopper in the preassembled position. At the same time the lumen must not be pushed so far into the stopper that vacuum is lost prior to injection of the other end of the needle into the vein. Therefore, the thickness of the diaphragm of the stopper must be great enough to accommodate the length of the lumen of the needle and yet still provide enough additional thickness to maintain a vacuum in the preassembled position. However, it is not easy to tell exactly how far the needle has been pressed into the diaphragm, since the rubber is not transparent. One attempt at solving this problem has been by the use of graduations or indicating marks on the holder to tell the operator when the lumen of the needle has been fully inserted within the diaphragm without having completely pierced the diaphragm. The use of guidelines is inconvenient to the operator, since it requires a rather careful placement of the tu within the holder.

To avoid reliance upon guidlines on the holder the current practice is to provide a rather thick diaphragm for the stopper, the thickness being intended to provide a safety margin in that the lumen can be imbedded in the stopper a substantial distance beyond the required minimum without any danger of premature loss of vacuum. However, the thicker diaphragm requires more force to complete the puncturing of the stopper from the preassembled position. The thrust action required to puncture the thicker stopper frequently results in the entire holder slipping slightly forward in the hands of the operator, permitting the end of the needle to jump from inside the vein through the vein wall into the surrounding tissue. If the blood is drawn from the tissue rather than from the vein there results a rather severe hematoma in the arm of the patient which produces a swelling, discoloration and pain.

To avoid the foregoing problems it has now been found that a blood sampling tube can be fitted with a stopper which does not rely upon the use of guidelines or entail the need for perfect alignment within the holder. In addition, the stopper utilized in the present invention has a thin diaphram which can be punctured with a very small thrust, thereby minimizing the chances of causing a hematoma because of the withdrawal of blood from the tissue rather than from the vein.

SUMMARY OF THE INVENTION Briefly, the pressure invention comprises a novel blood sampling tube for use with a blood sampling tube holder, said tube being provided at its open end with a stopper having along its longitudinal axis a thin imperforate diaphragm portion, above that of the needle to provide a sealing position for the needle, and above said hole a communicating entrance hole having at its widest point a diameter larger than that of said needle.

It is an object of the present invention to provide a novel evacuated blood sampling tube wherein relatively little force is required to puncture the stopper during the drawing of a blood sample.

A further object of the present invention is to provide an evacuated blood sampling tube having a stopper in the open end thereof which provides an aspirating position, sealing position and a puncturing position, and wherein little force is required to move from position to position.

These and other objects and advantages of my invention will be apparent from the more detailed description which follows.

DESCRIPTION OF PREFERRED EMBODIMENTS Tuming to the drawings:

FIG. I shows the blood sampling tube of the present invention loosely inserted in the holder;

FIG. 2 shows the blood sampling tube in the sealing position;

FIG. 3 shows the blood sampling tube in the aspirating position; and

FIG. 4 shows the blood sampling tube in the puncturing or blood drawing position.

Turning to the drawings in greater detail, the stopper I0 in the blood sampling tube 12 is initially loosely positioned in the holder 14, as shown in FIG. 1. The blood sampling tube 12 is then advanced within the holder 14 to the sealing position where the sealing hole 16 having a diameter slightly less than the diameter of the needle 18 seals on the inner end or scarf 20 of the needle as shown in FIG. 2. While this position is maintained, the other end 22 of the needle is inserted in the vein 24. The operator can then tell whether the needle has been inserted properly in the vein or not by drawing back on the tube so that the scarf 20 of the needle is positioned in entrance hole 26, as shown in FIG. 3, and observing the inner end of the needle. If the needle has been inserted properly in the vein, the veinous blood will appear in the form of droplets from around the opening in the stopper 10, as shown in FIG. 3. If the needle 18 has not been inserted properly in the vein, no blood will appear and the operator will then know to withdraw the needle and make a new insertion. Once it has been established that the needle 18 is properly inserted in the vein, the operator again advances to the sealing position which is that portion 16 of the hole in the stopper 10 having an inside diameter slightly less than the needle 18 and a length sufficient to cover the scarf 20. This transition from the aspirating position to the sealing position does not require any substantial thrust, since no puncturing is involved. In addition, the transition can be accomplished quickly so that only a few drops of aspirating blood are pennitted to escape before the operator is able to advance the blood sampling tube to a sealing position. The operator can detect when the needle is fully in the sealing position by feeling the tip of the needle contact the diaphram 28. Therefore, there is no need for any guidelines or indicating marks. In a sealing position no veinous blood can escape, since the scarf 20 of the needle is effectively sealed. Thereafter, the operator proceeds to the puncturing position shown in FIG. 4. This operation requires only a small force because of the thinness of the diaphragm 28. For this reason thereisno chance of the operator in applying the force necessary to pierce the diaphragm, inadvertently causing the needle to jump through the vein wall of the patient and cause a hematoma.

The entire length of the sealing portion 16 need not be of a diameter less than that of the needle. It is sufficient if at least at some point along the length of portion 16 the diameter is less thanthat of the needle so that an efiective seal is provided. As is apparent, any such point seal must be located in portion 16 at a distance from the diaphragm 28 greater than the length of scarf 20. The underside of the peripheral shoulsaid diaphragm portion, which has an inside diameter less than ders of the stopper normally rest against the end of the tube to form a seal. However, the means whereby the vacuum seal is maintained does not form a part of this invention. The structure of the holder and needle are familiar to those skilled in the art and hence need not be described in greater detail in this patent.

The face of the stopper having the entrance hole 26 is preferably domed or convex to facilitate the detection of blood when the parts are in the a'spirating position. However, this face can be flat or concave and still be provided with the same general type of hole construction, although the detection of the blood in the aspirating position would be more difficult It can be seen that in the present invention the novel blood sampling tube provides an aspirating means not available with the existing tubes. The invention also provides a sure way of avoiding the discharge of blood on the operator without the need for guidelines or a thick stopper. In fact, in the stopper of this invention the diaphragm normally has a thickness equal to only a fraction of the length of the scarf of the needle. As a result, little force is required to puncture at the time all is in readiness for the withdrawal of blood.

Having fully described the invention, it is intended that it be limited only by the lawful scope of the appended claims.

I claim:

1. A novel blood sampling assembly comprising a holder having a generally tubular transparent body, an end wall and an open end, the holder having affixed thereto a double-ended needle so that one end of the needle projects upwardly into said body and the other end is free for injection into the vein of the patient; and received in said holder an evacuated blood sampling tube comprising a transparent tube having an open end and a closed end, and a stopper within said open end, said stopper having along its longitudinal axis a thin imperforated diaphragm, above said diaphragm a hole at least as long as the scarf of said needle and of a constant diameter which is less than the diameter of said needle to provide a sealing portion for the scarf of said needle, and above said hole an outwardly tapering communicating entrance hole which leads to the face of the stopper and having at its widest point a diameter larger than that of said needle to facilitate the visual observation of blood while aspirating.

2. The blood sampling assembly of claim 1 wherein the stopper is provided with a peripheral shoulder which seals on the end of said tube. 

